Based on the traditional feature analysis of swelling
deformation, the swelling deformation of protected seam is mostly
represented by measuring the distance change of two fixed points in the
normal direction of protected seam, which only considers the deformation
feature of protected seam in the normal direction, while can not reflect the
lateral deformation of protected seam. Aiming at the problem that the
calculation results can not reflect the swelling deformation feature of coal
and rock body comprehensively and accurately, an analysis method of "four
fixed points enclosed area" on swelling deformation of protected seam in the
process of protective coal seam exploitation was proposed for the first
time, which analyzed the swelling deformation feature of protected seam
through the area swelling change analysis. The monitoring scheme, the
analysis and calculation method of area and the reasonable scale of "four
fixed points enclosed area" were put forward in the engineering practice and
laboratory. Taking the similar simulation of multi coal seam mining in Shaqu
mine as background, the accuracy of "four fixed points enclosed area"
analysis method under different scales were analyzed. The results showed
that it has higher accuracy than the "two fixed point" analysis method. The
more area cells divided in the enclosed region with 1 times scale of
protected seam thickness, the higher the calculation accuracy of swelling
deformation.